Modifications in the electrochemical and spectral properties of hemin (Hm) adsorbed on roughened Ag electrodes in an aqueous electrolyte induced by brief exposure to mildly acidic solutions containing NO were examined in situ surface-enhanced Raman scattering (SERS) using Q band excitation. Careful inspection of the data indicated that the SERS spectrum of the NO-Hm adduct resembled that of adsorbed Hm, rather than its reduced counterpart, measured under otherwise identical conditions.

The study monitored the in situ normal incidence reflectance spectra of polycrystalline Pt microelectrodes as a function of the applied potential in aqueous 0.5 M H2SO4 using a He-Ne laser source (663nm) and a beam splitter/microscope objective arrangement. Analysis of the results made it possible to extract contributions to the current derived from oxide formation during oxidation of adsorbed and bulk CO, based strictly on the optical response.

In situ Raman microscopy of a single graphite microflake electrode in a Li+ - containing electrolyte

Article Abstract:

The indirect photocatalytic reduction of four metal ions, Cd(super 2+), Zn(super 2+), Mn(super 2+), TI(super +), using formate radical anions (CO(sub 2)(super .-)) generated in UV-irradiated aqueous TiO2 suspensions are described. The trends in the reactivity of these four metal ions are compared with corresponding rate constants that are reported for the homogeneous reactions of these metal ions with (CO(sub 2)(super .-)) in aqueous media.